Publisher's blurb
Statistics for Physical Sciences is an informal, relatively short, but systematic, guide to the more commonly used ideas and techniques in statistical analysis, as used in physical sciences, together with explanations of their origins. It steers a path between the extremes of a recipe of methods with a collection of useful formulas, and a full mathematical account of statistics, while at the same time developing the subject in a logical way. The book can be read in its entirety by anyone with a basic exposure to mathematics at the level of a first-year undergraduate student of physical science and should be useful for practising physical scientists, plus undergraduate and postgraduate students in these fields.
Almost all physical scientists at some time come into
contact with statistics. This is often initially during their
undergraduate studies, but rarely is it via a full lecture
course. Usually some statistics lectures are given as part of
a general mathematical methods course, or as part of a
laboratory course. Neither route is entirely satisfactory. The
student learns a few techniques, typically unconstrained
linear least-squares fitting and analysis of errors, but
without necessarily the theoretical background that justifies
the methods and allows one to appreciate their limitations. On
the other hand, physical scientists, particularly
undergraduates, rarely have the time, and possibly the
inclination, to study mathematical statistics in detail. What
I have tried to do in this book is therefore to steer a path
between the extremes of a recipe of methods with a collection
of useful formulas, and a detailed account of mathematical
statistics, while at the same time developing the subject in a
reasonably logical way. I have included proofs of some of the
more important results stated in those cases where they are
fairly short, but this book is written by a physicist for
other physical scientists and there is no pretence to
mathematical rigour. The proofs are useful for showing how the
definitions of certain statistical quantities and their
properties may be used. Nevertheless, a reader uninterested in
the proofs can easily skip over these, hopefully to come back
to them later. Above all, I have contained the size of the
book so that it can be read in its entirety by anyone with a
basic exposure to mathematics, principally calculus and
matrices, at the level of a first-year undergraduate student
of physical science.
Statistics in physical science is principally concerned with
the analysis of numerical data, so in Chapter 1 there is a
review of what is meant by an experiment, and how the data
that it produces are displayed and characterized by a few
simple numbers. This leads naturally to a discussion in
Chapter 2 of the vexed question of probability – what do we
mean by this term and how is it calculated. There then follow
two chapters on probability distributions: the first reviews
some basic concepts and in the second there is a discussion of
the properties of a number of specific theoretical
distributions commonly met in the physical sciences. In
practice, scientists rarely have access to the whole
population of events, but instead have to rely on a sample
from which to draw inferences about the population, so in
Chapter 5 the basic ideas involved in sampling are discussed.
This is followed in Chapter 6 by a review of some sampling
distributions associated with the important and ubiquitous
normal distribution, the latter more familiar to physical
scientists as the Gaussian function. The next two chapters
explain how estimates are inferred for individual parameters
of a population from sample statistics, using several
practical techniques. This is called point estimation. It is
generalized in Chapter 9 by considering how to obtain
estimates for the interval within which an estimate may lie.
In the final two chapters, methods for testing hypotheses
about statistical data are discussed. In the first of these
the emphasis is on hypotheses about individual parameters, and
in the second we discuss a number of other hypotheses, such as
whether a sample comes from a given population distribution
and goodness-of-fit tests. This chapter also briefly describes
tests that can be made in the absence of any information about
the underlying population distribution.
All the chapters contain worked examples. Most numerical
statistical analyses are of course carried out using
computers, and several statistical packages exist to enable
this. But the object of the present book is to provide a first
introduction to the ideas of statistics, and so the examples
are simple and illustrative only, and any numerical
calculations that are needed can be carried out easily using a
simple spreadsheet. In an introduction to the subject there is
an educational value in doing this, rather than simply
entering a few numbers into a computer program. The examples
are an integral part of the text, and by working though them
the reader’s understanding of the material will be reinforced.
There is also a short set of problems at the end of each
chapter and the answers to the odd-numbered ones are given in
Appendix D. There are three other appendices: one on some
basic mathematics, in case the reader needs to refresh their
memory about details; another about the principles of function
optimization; and a set of the more useful statistical tables,
to complement the topics discussed in the chapters and to make
the book reasonably self-contained.